My last name is wrong

In the email I received my last name is Collins which it's not, I called customer service and they assured me the problem would be escalated to a manager or something and it should be corrected in a few days and it's not. Halp me

Did you by chance get the account with your maiden, or a previously married name that was yours at the time? I did and mine is still in my maiden name because I'm too lazy to send a copy of my marriage certificate. I really need to do that I suppose but, honestly it keeps skipping my mind.